Irreversibly closable flow control clamp

ABSTRACT

A flow control clamp having a first member and a second member movable from a first open position to a second irreversibly closed position wherein flow through a tube associated with the clamp is irreversibly prevented and cannot be restored. Systems and methods using such clamps are also disclosed.

RELATED APPLICATIONS

This application is a continuation of application U.S. patentapplication Ser. No. 12/401,332, filed on Mar. 10, 2009, which is acontinuation of U.S. patent application Ser. No. 10/501,571, filed onApr. 27, 2005, which is a national stage entry of InternationalApplication No. PCT/US03/01758, filed on Jan. 21, 2003 and designatingthe United States, and claims the benefit of U.S. Provisional PatentApplication Ser. No. 60/353,930, filed on Jan. 31, 2002, whichapplications are incorporated by reference herein.

The present application relates to clamps for controlling the flow ofliquid through a flexible tube. More particularly, the present inventionrelates to flow control clamps that can be substantially irreversiblysecured in a closed position, thereby discouraging reopening of the flowpath of the tube.

BACKGROUND OF THE INVENTION

A disposable plastic container and tubing set or fluid circuit istypically used for collecting blood from a donor. The disposable bloodcollection set includes a venipuncture needle for insertion into the armof the donor. The needle is attached to one end of a flexible plastictube which provides a flow path for the blood. The other end of theplastic tube is attached to one or more plastic bags or containers forcollecting the withdrawn blood.

The blood collection set may also include a sampling sub-unit. Thesampling sub-unit allows for collection of a sample of blood, whichsample can be used for testing of the blood. Preferably, the sample isobtained prior to the “main” collection of blood. Collecting the sampleprior to the main collection reduces the risk that bacteria residing onthe donor's skin where the needle is inserted (i.e., in particular, thesmall section of detached skin commonly referred to as the “skin plug”)will not enter the collection container and contaminate the bloodcollected for transfusion. Thus, it is preferred that the blood sampleswhich may include the skin plug, be diverted from the main collectioncontainer.

An example of a blood collection set with such a “pre-donation” samplingsub-unit is described in U.S. patent application Ser. No. 09/364,628filed Jul. 29, 1999, and U.S. patent application Ser. No. 09/492,060filed Jan. 27, 2000, which are incorporated by reference herein. Thecollection sets described therein include a needle and a length oftubing, one end of which is attached to the needle and the other end ofwhich is attached to one or more collection containers. The tubing setalso includes an additional line which is branched from the main line ata Y-connection site in the tubing set. The branched line is attached toa sampling pouch for collecting a smaller volume of blood from whichsamples may be obtained.

The sampling sub-unit may further include a pre-attached holder forreceiving blood sample vials or tubes. The holder is connected to theoutlet port of the sampling pouch and includes a needle in the holderinterior. When the blood sample vial is inserted into the holder, theneedle pierces the rubber cap (septum) of the vial and blood from thesampling pouch is drawn into the vial. The blood-filled vial is removedfrom the holder and the procedure may be repeated with as many vials asrequired.

The blood collection set described above also includes flow controlclamps for controlling the flow of biological fluid (e.g., blood)through the set and to the sampling pouch and/or collection container.Flow control clamps commonly used are the Roberts-type clamps, which arewell known in the art. The Roberts-type clamps are placed on the tubingline leading to the blood collection container and on the tubing lineleading to the sampling pouch. A Roberts-type clamp is typically madefrom a strip of plastic. The ends of the strip are curved toward eachother to provide two “legs” which are adapted to engage each other in asnap-fit, spring relation. The body of the clamp includes a pair ofapertures through which the tubing passes.

The clamp further includes a pair of projections or tube contactingmembers which compress the tubing when the body of the clamp isdepressed, thereby restricting flow, through the tube. Clamps of thistype are generally described in U.S. Pat. Nos. 3,942,228, 6,089,627 and6,113,062, all of which are incorporated herein by reference.

The clamps described in these patents also typically include means forlocking the legs together and release means which, when actuated by thetechnician, disengages the locked legs of the flow control clamp.Disengagement of the ends decompresses the tube and permits fluid flowthrough the flow path. Thus, by selectively opening and closing thedifferent flow paths (by depressing or releasing the clamps), thetechnician can control the flow of blood from the donor, diverting theblood to the desired container or sampling pouch, as necessary.

In certain instances, however, it may not be desirable to reopen aclosed flow path. This may particularly be the case when drawing bloodsamples from the sampling pouch into sample vials. For example, when thesampling pouch is filled with the required or desired volume of blood(for sampling), the line from the donor to the pouch is typically closedby the Roberts-type clamp, and remains closed as the sampling vials arefilled. After clamping the sampling line closed, technicians are furtherinstructed to more permanently seal the line using metal clips or byheat-sealing the line in ways that will be known to those in the field.Sealing the sampling line substantially ensures that airborne bacteriaor other contaminants that may enter the set through the samplingsub-unit do not contaminate the remainder of the set, including theneedle and tube leading to the collection container. In short, the clipsor heat seal provide a sterile barrier to the remainder of the set.

Unfortunately, on occasion, prior to permanently sealing the samplingline, some technicians have been known to unclamp the sampling line inorder to draw additional blood into the pouch so that additional samplevials may be filled. However, by doing so, the system becomes “open” andcontaminants introduced from the outside environment may enter thesystem. Current flow control clamps are readily and easily openable, anddo not provide a disincentive to drawing additional blood into thesampling pouch. If the clamp could not be so readily released from theclosed position, the technician would not have the option of reopeningthe line but would, hopefully, proceed with permanently sealing the lineto form the sterile barrier. Accordingly, it would be desirable toprovide a clamp that discourages and substantially prevents thereopening of the sampling or other blood tube line.

SUMMARY OF THE INVENTION

In one aspect, the present invention is directed to a flow control clampthat includes a flexible body. The body has a first leg and a second legdisposed in a generally facing relationship. The legs are moveablebetween a first spaced apart position and closed position. The clampincludes two apertures in the body for receiving a flexible tubetherethrough and between the legs. The clamp further includes at leastone tube contacting member carried by one of the legs for clamping thetube when the legs are in the closed position. The first and second legsinclude surfaces disposed to irreversibly secure the legs together inthe closed position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a blood tubing set including a flowcontrol clamp embodying the present invention;

FIG. 2 is a perspective view of a flow control clamp embodying thepresent invention;

FIG. 3 is a plan view of the flow control clamp of FIG. 2 taken fromlines 3-3 of FIG. 2;

FIG. 4 is a plan view of the flow control clamp of FIG. 2 taken fromlines 4-4 of FIG. 2;

FIG. 5 is a plan view of the flow control clamp of FIG. 2 from lines5-5;

FIG. 6 is a plan view of the flow control clamp of FIG. 2 taken fromlines 6-6;

FIG. 7 is a cross-sectional, side view of the flow control clampembodying the present invention in the open position;

FIG. 8 is a cross-sectional, side view of the flow control clampembodying the present invention in the irreversibly locked position;

FIG. 9 is a side view of an alternative embodiment of the flow controlclamp of the present invention;

FIG. 10 is a side view of another alternative embodiment of the flowcontrol clamp of the present invention;

FIG. 11 is a side view of another alternative embodiment of the flowcontrol clamp of the present invention; and

FIG. 12 is a side view of another alternative embodiment of the flowcontrol clamp of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

Turning now to the drawings, FIG. 1 depicts a blood collection set 10 ofknown type that is used in the collection of blood from a donor. Tubingset 10 includes a venipuncture needle 12 and a length of tubing 14.Tubing 14 branches at Y-connector 16 into tubing segment 144 and tubingsegment 14 b. Tubing segment 14 a provides a flow path to a collectioncontainer 18 and tubing segment 14 b provides a flow path to a samplingpouch 20. The sampling pouch may also include a holder 21 for receivinga blood sampling vial or tube. (Also shown is a needle protector 16 forstoring the needle after use.)

In the blood tubing sets of the type shown in FIG. 1, tubing segments 14a and 14 b are passed through flow control clamps 22 and 30 which may bea standard Roberts-type clamp and an irreversibly closable flow controlclamp embodying the present invention. As used herein, the termsirreversibly closed or closable means that the flow control clamp, oncein the closed position, is not readily releasable from the closedposition in the normal and intended mode of operation. An “irreversibly”closed or closable flow control clamp can only be released from theclosed and locked position by extraordinary and unintended manipulationof the clamp, including breakage of the clamp. A flow control clamp thatis “irreversibly” closed or closable includes no release members suchas, but not limited to, those described in U.S. Pat. Nos. 3,942,228,6,089,527, 6,113,062.

Thus, whereas flow control clamp 22 can be selectively opened andclosed, as desired, clamp 30, made in accordance with the presentinvention, once closed, remains irreversibly closed.

Turning now to FIG. 2, flow control clamp 30 of the present inventionincludes a generally curved, bent or otherwise non-linear body 34(described in more detail below). Preferably, flow control clamp 30 maybe made of any flexible, moldable, plastic material that can be steamsterilized. In addition, flow control clamp 30 and body 34 should bemade of a material that is strong, yet sufficiently flexible so that theclamp can be flexed and squeezed by the technician without breaking.Examples of suitable materials are many, of the known plastic materialstypically used in the medical field, including, but not limited topolyoxymethylene and polypropylene. Most preferred of theabove-identified materials is polyoxymethylene, such as thepolyoxymethylene known as Hostaform™ available from Ticona of Frankfurt,Germany. In addition, other materials that can be sterilized by otherforms of sterilization, such as gamma sterilization, may also be used.One such material is a terpolymer of acrylonitrile, butadiene andstyrene (ABS).

As further shown in FIG. 2, flow control clamp 30 includes body 34 thathas two legs 36 and 38. Legs 36 and 38 are disposed in a generallyfacing relationship relative to each other. Legs 36 and 38 are initiallyin a spaced apart position as shown in FIG. 7, and are movable from thespaced apart position toward each other and to a closed position.

Body 34 further includes apertures 40 and 44 for receiving a length ofplastic tubing therethrough. As shown in FIG. 2, apertures 40 and 44 arepreferably circular or oval-like and are entirely contained within body34 of flow control clamp 30. Thus, when a length of tubing 43 isinserted through apertures 40 and 44, the apertures completely encloseand surround the tubing at the point where the tubing extends throughthe apertures. Also, it may be preferable that apertures 40 and 44 begenerally aligned with each other and not substantially offset relativeto one another. This provides, among other things, for easier threadingof the length of tubing 43. Alternatively, apertures need not completelysurround the tube, but instead may include lateral slots, as described,for example, in U.S. Pat. No. 6,113,062. The lateral slots extend to theouter edge of the body so that during insertion of the tube, the clampcan be laterally slipped on the tube (as opposed to threading).

Flow control clamp 30 includes one or more tube contacting members 48and 50. Tube contacting members 48 and 50 are carried by legs 36 and 38,respectively. As shown in FIG. 2, tube contacting members 48 and 50 maybe teeth-like projections which compress the tubing when the clamp isclosed. Alternatively, tube contacting members 48 and 50 may simply beblunt, oppositely facing surfaces. Although two oppositely facingcontacting members are shown in FIG. 2 and are preferred, it will beunderstood that flow control clamp 30 of the present invention mayinclude only one tube contacting member carried by one of the legs 36 or38.

The outer surface 52 of flow control clamp 30 is generally flat andsmooth. However, outer surface 52 may include members that are roughenedor textured to provide some friction when contacted by the fingertips ofthe technician during operation. As shown in FIGS. 3 and 4, outersurface 52 of body 34 includes ribbed members 54 and 56, which providesuch a frictional surface for contacting by the fingers of thetechnician during closure and compression of flow control clamp 30.

As best shown in FIGS. 7 and 8, flow control clamp 30 is substantiallyfree of any sharp corners or edges. For example, bends 58, 60 and 62 inbody 34 are not abrupt, sharp corners, but are gradually curved androunded. In addition, edges 63 of body 34 are preferably rounded orbeveled. A flow control clamp 30 that is substantially free of sharpcorners and edges and is more rounded or beveled, like the flow controlclamp shown in FIGS. 7 and 8, ensures that the flow control clamp willnot puncture the packaging of blood processing sets, thereby maintainingsterility of the packaged set.

As discussed generally above, where the blood processing set includes asampling pouch of the type shown in FIG. 1, it may be desirable toprovide a flow control clamp 30 that provides an additional level ofsterility maintenance by discouraging and perhaps even preventing thetechnician from reopening a previously closed clamp. This way, thesterility of the remainder of the blood processing set will bemaintained and will not be compromised by bacteria from the outsideenvironment.

Accordingly, flow control clamp 30, and more particularly, legs 36 and38 include surfaces that are disposed for irreversibly securing togetherlegs 36 and 38 when the legs of flow control clamp 30 are moved from aspaced-apart position to the closed position, as shown in FIGS. 7 and 8.

Many different means for securing legs 36 and 38 together in a way thatprevents easy reopening by the technician are contemplated by thepresent invention. For example, flow control clamp 30 may include meanson the leg surfaces for interlocking legs 36 and 38. Specifically, asshown in FIGS. 7 and 8, leg 36 of flow control clamp 30 may include apair of spaced-apart walls 66 and 68. Spaced-apart walls 66 and 68define a slot 70 for receiving an extension 72 carried by leg 38. One ofthe spaced-apart walls 66 or 68 may further include a lip 74 thatprojects into slot 72, while the extension 72 includes a hook 76 thatprojects toward the wall 66.

As the legs 36 and 38 are moved from the spaced-apart position, asgenerally depicted in FIG. 7, to the closed position, tube contactingmembers 48 and 50 compress the tube 43, thereby restricting flowtherethrough. As flow control clamp 30 is compressed further, extension72 is outwardly displaced by wall 66 and enters slot 70. As hook 76contacts lip 74, extension 72 is again outwardly displaced until itclears lip 74. Once clear of lip 74, extension 72 snaps forward towardwall 66, and hook 76 engages lip 74 to effectively close and lock flowcontrol clamp 30.

Wall 68 prevents release or further outward displacement of extension 72from the closed position, thereby resulting in an “irreversibly closed”flow control clamp 30. As shown in FIG. 8, wall 68 is a thicker and aless flexible wall than, for example, wall 66, thereby providing morestrength to wall 68 and making it even more difficult to releaseextension 72. As will be appreciated by those in the field, flow controlclamp 30 does not include any tabs or other means for readily releasingextension 72. Thus, flow control clamp 30 remains in the closedposition.

FIGS. 9-12 include additional means for securing legs 36 and 38 in an“irreversibly closed” position. For example, as shown in FIG. 9,extension 72 may include a peg, and wall 66 includes a mating notch 84for receiving peg 86 of extension 72. Extension 72 enters slot 70 in themanner generally described above, until peg 86 snaps into notch 84. Wall68 again prevents outward movement of extension 72, thereby retainingflow control clamp 30 in an “irreversibly closed” position.

FIG. 10 is an alternative embodiment where extension 72 includes a notchfor receiving lip 74 of wall 66. In FIG. 11, lip 74 is located on wall68 and is engaged by hook 76, as previously described.

FIG. 12 shows yet another alternative embodiment of the flow controlclamp 30 of the present invention wherein leg 36 includes a single wall85 projecting toward the interior (i.e., toward leg 38) of the flowcontrol clamp 30. Leg 38 includes an extension, likewise, projectingtoward the interior (i.e., and toward leg 36) of the flow control clamp30. In order to secure legs 36 and 38 in the “irreversibly closed”position, one of the legs may include a socket 86, and the other of thelegs may include a ball 8B for insertion into socket 86. This way, as inthe previous embodiments, flow control clamp 30 may be closed or lockedin the “irreversibly closed” position.

It will be appreciated that the description set forth above has beenoffered for illustrative purposes only. Other embodiments and othermodifications to the flow control clamp shown and described above mayalso be included within the scope of the present invention. The abovedescription is not intended to limit the scope of the invention of thisapplication, which is as defined in the claims below.

1-36. (canceled)
 37. A flow control device comprising: a body having afirst leg and a second leg, said legs being movable from a first spacedapart position to a second irreversibly closed position wherein one ofsaid first and second legs includes in an inwardly extending memberhaving an engagement member and the other of said first and second legsincludes a pair of inwardly extending members, at least one of whichincludes a first surface engaged by said engagement member when saiddevice is in said second irreversibly closed position and the other ofsaid pair of inwardly extending members limits movement of said inwardlyextending member having said engagement member away from said firstsurface and prevents disengagement of said engagement member from saidengagement surface; at least one opening provided in said body forreceiving a tubing segment therethrough and between said legs; and atleast one tube contacting member carried by one of said legs forclamping said tubing segment when said legs are in the secondirreversibly closed position.
 38. The device of claim 37 wherein saidpair of inwardly extending members define a space therebetween, wherebymovement of said legs from said spaced apart position to saidirreversibly closed position introduces said inwardly extending memberhaving said engagement member into said space.
 39. The device of claim38 wherein said first leg comprises a lip for said engagement member forengaging the first surface of one of the pair of inwardly extendingmembers of the second leg when the device is in said irreversibly closedposition.
 40. The device of claim 38 wherein one of said pair ofinwardly extending members is more rigid than said other of said pair ofinwardly extending members.
 41. The device of claim 38 wherein said bodyis made of a polymeric material selected from the group consisting ofpolyoxymethylene and polypropylene.
 42. The device of claim 37 furthercomprising a tube contacting member carried by the other of said legsbeing spaced and separate from said pair of inwardly extending membersfor clamping said tubing segment between said contacting members whensaid legs are in the second irreversibly closed position.
 43. The deviceof claim 37 wherein the outer surface of said body is free of sharp endsand corners.
 44. The device of claim 37 wherein said at least oneopening in said body comprises an aperture enclosed by said body. 45.The device of claim 37 wherein the device does not include a releasingmember for releasing said device from said irreversibly closed position.46. The device of claim 37 wherein the pair of inwardly extendingmembers on said other of said first and second legs comprises aspaced-apart solid walls defining a slot for receiving the inwardlyextending member on said one of said first and second legs.
 47. Thedevice of claim 37 comprising two openings provided in said body forreceiving a tubing segment therethrough.
 48. The device of claim 47wherein at least one of said openings in said body comprises an apertureenclosed by said body.
 49. The device of claim 42 wherein the bodydefines a closed end where the first and second legs connect to eachother, and at least one of the tube contacting members is carried on itsrespective leg between the pair of inwardly extending members and theclosed end of the body.